The problem is that land is not infinite. Going with your example, if someone clears 100,000 acres, have they not deprived others of the natural use of the land? If a small percentage of the population owns most of the land and cuts down all the trees (for their sole profit), how is that no worse than you dumping toxic waste on "my" land?
The way property generally works is first-come, first-served. Let's say I find a gold vein, and mine it and refine it and cast it into ingots. That would give me 100% of the ownership of that gold. If you walk by the same area and "discover" my ingots, in the exact same way that I found that same gold in the ground before, you get 0% claim of ownership over that gold.
It's the same with patents, trademarks, and other IP. Whoever makes the first claim gets the rights.
The way property generally works is first-come, first-served. Let's say I find a gold vein, and mine it and refine it and cast it into ingots. That would give me 100% of the ownership of that gold. If you walk by the same area and "discover" my ingots, in the exact same way that I found that same gold in the ground before, you get 0% claim of ownership over that gold.
It's the same with patents, trademarks, and other IP. Whoever makes the first claim gets the rights.